A growing network of NASA cameras is providing dramatic images of meteors as they streak across the night sky, and may eventually protect astronauts in space.
"If you have an object that's picked up by multiple cameras, you can figure out speed, direction and height," said David Dundee, an astronomer at the Tellus Science Museum in Cartersville, Ga., which houses one of the cameras on its roof. "You can actually plot the orbit of where these things come from."
The Tellus camera is one of four NASA "all sky" cameras already operational in the Southeast. The space agency is completing a network of 15 cameras east of the Mississippi River, with plans to expand nationwide, to help compute the routes of these objects.
By determining the paths of meteoroids (the term for space debris outside the atmosphere), scientists hope to develop enough advance warning to keep astronauts out of harm's way. Engineers also hope to make spacecraft more resistant to strikes from meteoroids as they learn more about the objects' sizes and speeds.
"The major meteor showers, we pretty much know about," Dundee said. "It's the other minor showers and streams we don't know about, and then the sporadic meteors that are not associated with showers. We're trying to get a handle on what the rate is and from where."
Here on Earth, the atmosphere offers excellent protection against the estimated 100 tons of space dust, gravel and rocks that enter it each day. More than 99 percent of this material burns up completely before getting anywhere near the ground.
Such was the case back in May, when the Tellus camera captured dramatic video of a 6-foot wide meteor that blazed through the upper atmosphere at 86,000 mph. The intense friction, which ultimately caused the object's demise, lit up the night sky. "Had it hit the ground, it would have been the equivalent of a thousand tons of TNT," Dundee said.
"Fortunately, it was icy. It disintegrated." Dundee's museum houses a collection of meteorites (the term for those rare meteors that reach the ground), including a tangerine-size object that crashed through the roof of an unoccupied Cartersville house back in 2009.
While the hole it left in a ceiling tile (also on display) leaves little doubt as to its origin, Dundee said many objects people believe to be meteorites turn out to be "meteor-wrongs."
However, he said the NASA cameras may help scientists determine the general area where a meteor may have landed -- helping them increase their collections on the ground, while improving safety in space.